The chin up is one of the most challenging bodyweight exercises, it also offers a huge range of benefits. Some gym members will find chin ups easy, but the vast majority of gym members find chin up incredibly difficult to master.
Working your way up to performing your first few chin ups will leave you with one of the greatest feelings of accomplishment that you can experience in a gym.
In this article, we will be discussing which muscles are worked during a chin up, and the differences between chin ups and traditional pull ups.
What Muscles Do Chin Ups Work?
Chin ups are usually described as an upper back exercise, or a bicep exercise. But in reality, the chin up works a wide range of muscles. Here are the muscles worked during a chin up:
- Traps (Trapezius)
- Lats (Latissimus dorsi)
- Rhomboids
- Teres Major
- Scapular & Shoulder Stabilisers
- Biceps
- Abdominals
- Forearms
We will take a look at each muscle in turn and explain what role they play in the chin up exercise.
Trapezius Muscle
The main function of your trapezius muscle during a chin up is to stabilise the shoulders, there are other muscles that work alongside the traps, but it is the traps that do the majority of the work. Your trapezius muscle is split into three parts: the upper, middle, and lower. All three parts contribute to shoulder stability.
Latissimus Dorsi
The latissimus dorsi muscles are prominent muscles in most pull up variations, yet they are less prominent than usual during a chin up due to the narrow grip used. Even so, the lats are worked more than any other muscle in the upper back and are the third most used muscle overall during a chin up. The role of the lats is to pull your arms down and inwards in the direction of your pelvis.
Rhomboids
The rhomboids are situated underneath your trapezius and offer a similar function, moving the scapula and helping you to pull yourself up and lower yourself back down again.
Teres Major
While the rhomboids work with the traps, the teres major works with the lats, helping your arm to pull down and towards your pelvis.
Scapular & Shoulder Stabilisers
These are the muscles of your rotator cuff, and their function is to stabilise the shoulders and the scapular. Without them, you would not have the stability to pull yourself up and down during a chin up.
Biceps
According to a 2018 study by the Journal of Physical Fitness, Medicine & Treatment in Sports, the bicep muscle is the second most activated muscle during chin ups. This does not mean that the biceps are doing more work than the lats or the traps, just that they are activated more. In other words, your biceps will get a better workout from chin ups than your back, but your back does more of the work.
Abdominals
That same study found that the most activated muscles during a chin up are the rectus abdominus muscles. Their function is to keep your torso and your legs stable while you perform your chin up. It may be surprising how crucial the abs are for chin ups, but next time your abs are hurting try a chin up and you will see!
Forearms
Chin ups require a firm grip of the bar, which taxes your forearm muscles quite hard. Many people who struggle with chin ups or pull ups find that it is weak forearms that are holding them back.
Other Muscles
The pectorals are also activated during chin ups, as are the muscles of the spine, but they are not as prominent as the muscles mentioned above.
Do Chin Ups Work Shoulders?
After reviewing the muscles worked during a chin up you may be wondering whether chin ups work your shoulders at all. The answer is, not really. Some muscles in the upper back (rhomboids, teres major, scapular and shoulder stabilisers) are grouped into shoulder muscles. But deltoids are not particularly worked during a chin up.
Chin Up vs. Pull Up
Chin ups and pull ups are often mistakenly conflated, but they are two different exercises. The clearest difference between both movements is the grip type and position of the hands on the bar.
Pull ups require a pronated (overhand) grip where your palms point outwards so that they are facing away from you. Chin Ups require a supinated (underhand) grip where your palms point inwards so that they are facing you.
Typically, if someone can perform 10 chin ups then they can usually perform around 6 pull ups, due to the differences in grip, muscles used and strength.
Both exercises will primarily train your back, lats and biceps, however, there are some slight differences in the degree in which those muscles get worked. Pull ups place more emphasis on the upper back, while chin ups place more emphasis on the biceps.
Research suggests that the general pattern of sequential muscle activation with both pull-ups and chin-ups start with the lower trapezius and pectoralis major and completed with biceps brachii and latissimus dorsi recruitment.
The pectoralis major and biceps brachii had significantly higher muscle engagement during the chin-up than during the pull-up, whereas the lower trapezius was significantly more active during the pull-up.
Two similar, yet different exercises with some obvious benefits and differences between the two, most notably biceps involvement with the supinated position of the forearm during the chin up.
Academics also suggest that chin-ups are going to involve a larger amount of muscle and are much easier to progress on weighted and progression, which is the key to results. Chin ups also allow a greater range of motion when done properly because they allow the elbows to travel farther behind the back causing a greater contraction.
So, if your goal is to build muscle or get stronger, it might be a good idea to use both exercises in a complementary way to support a well-rounded upper body workout plan.
Final Thoughts
Chin ups are a superb upper back and bicep exercise, that will also work your abs. They provide a greater range of motion than traditional pull ups, and are more accessible due to being slightly easier to perform. Using both chin ups and pull ups (or their assisted variations) is a great way to add some diversity to your training program.
